This proposal concerns the relationship of chromatin components and structure to control of gene expression. Specifically, we will study transcription in vitro of adenovirus DNA complexed with viral histone-like proteins. This system represents an interface between two important and fruitful lines of research: studies of the control of transcription using cell-free extracts and defined DNA templates, and our own studies of adenovirus chromatin structure throughout the infectious cycle. Viral cores, defined DNA-protein complexes isolated from adenovirions, will be used as templates for transcription. Resulting RNA will be mapped precisely and compared to transcripts resulting from deproteinized DNA templates. Disruption and modification of cores will be used to ascertain which features of this chromatin organization govern the changes in specificity observed.